Electric fence impulse control system



June 10, 19479 L, E2GREENLEE 2,422,012

ELECTRIC FENCE IMPULSE CONTROL SYSTEM Filed April 6, 1944 Pate ed Ju 1 9 7 UNITED STATES PATENT OFFICE ELECTRIC FENCE IMPULSE CONTROL STEM 8 Claims. 1

This invention relates to an improved system of electric fence impulse control to confine livestock or other animals.

The invention relates primarily to means of construction of the controlling apparatus and stock enclosure in such a way that the mechanism does not operate unless an animal actually touches some part of the enclosure.

A further object of the invention is to provide a mechanism that will use much less current than other systems now in use. I

Another primary object of the invention is to provide a means for greatly reducing the mechanicalwear on circuit breakers and contact points. That my invention may be more fully understood, reference is made to the accompanying drawings which form a part of this description, in which:

Figure 1 shows a wiring diagram of the invention.

Figure 2 shows a modified circuit for use with transposed fence wires.

Figure 3 shows essentially the same circuit as shown in Figure 2, connected for use with a single fence wire, and with input sensitivity control.

The interrupter I shown in Figures 1 to 3 consists of one movable and one fixed contact, normally closed, and so designed and mounted that the magnetic attraction from the iron core of the fence transformer T will cause these contacts to open and thus interrupt the circuit. In its simplest form, the interrupter I and transformer T could be a spark coil of the automotive ignition type. For use with electric fencing, a rotor mechanism or other type of mechanical delay action is usually provided to slow down the frequency of operation of the interrupter to one or two contacts per second. The combination of interrupter I, condenser C1 and fence transformer T may be considered as a unit which may be chosen 'from any one of several such devices now on the market.

Details of the actual mechanical construction of such a device have been purposely omitted from my explanation because my invention does not relate to the construction of such devices. When operating at 1 second intervals (electric. fence safety regulations now call for an on period of second or less and on off period of at least second) this contact mechanism will operate 3600 times in one hour, and will operate 86,400 times in 24 hours. The system of electric fencing which I have invented operates on an average of 15 or 20- times during a. 24 hour period. The saving in wear and current is quite obvious. Another very important point to consider is the fact that with my system the shock impulse can be made much stronger than with the method described above. This is true because with a mechanism making 86,400 impulses a day, each separate impulse must be very Weak or the battery would be exhausted very quickly. Manufacturers of such devices, in order to secure reasonably satisfactory battery life, have constructed mechanisms in such a way that the shock impulses are barely strong enough to control the animals when batteries are new, fences are well insulated, and the mechanism is in perfect working order. With a partly run-down battery or partly grounded fence, such a mechanism becomes worthless for the purpose for which it was intended, and this is one of the primary reasons why such mechanisms have not come into more general use, although some of them were patented almost years ago.

In Fig. 1, the fence wires Fl and F2 are supported on insulators 5 attached to posts M and are spaced closely together. An animal crowding into the fence will form a connection between Fl and F2 by touching these two wires. A drop in the electrical resistance between Fl and F2 is suflicient to actuate the sensitive vacuum tube or electronic relay V. Relay tube V is a triode or three-element tube containing a grid lll, plate H, and cathode 9 and filled with a conductive gas. Tube V is so constructed that the application of a small voltage to the grid l0 will cause a current to fiow between plate H and cathode 9 and this current is used to operate relay R2. Tube V remains non-conductive when no voltage is applied to the grid l0, which is connected to Fl through potentiometer l5. Fence wire F2 is connected to battery B in such a way as to apply the voltage from battery B between cathode 9 and grid l0 whenever a connection is made between FI and F2. Potentiometer I6 is connected between fence Fl and cathode 9 and serves the purpose of limiting and controlling the sensitivity of relay-tube V. Whenever the tube V becomes conductive, current flows from battery B through relay armature l3 to upper fixed contact l2, to cathode 9, to plate I I, through relay coil l5, and back to battery B. Armature I3" is then attracted to fixed contact l4 and the circuit is completed between battery B and the primary P of fence transformer T through interrupter I. A shock impulse then appears between F2 and ground. The charge stored in condenser C2 serves to de lay the opening of relay armature l3 until the interrupter I has had an opportunity to function. Relay R2 serves the double purpose of connecting the primary of the fence transformer to the battery and simultaneously opening the circuit to the cathode of the relay-tube, so that the tube will become non-conductive and the entire system will be ready for another cycle of operation upon the opening of the relay armature. However, the fence wire F2 receives intermittent impulses through the action of interrupter I as long as Fl and F2 are contacted, and the frequency of these impulses will depend on the timing of the interrupter I.

Figure 2 shows a modified circuit with transposed fence wires. The cathode 9 of tube V is connected to interrupter I along with the primary P of the fence transformer, and upper relay contact l2 can thus be omitted. When switch 20 is closed and a single wire fence connected to F! the impulse control mechanism is shorted. This is also true for Fig. 3. In Fig. 2, a contact between FI and F2 or between F2 and round is sufficient to actuate relay tube V because Fl is connected to the ground through the secondary S of the fence transformer, which is also connected to the opposite pole of battery B so that the E. M. F. of B is across the plate I l and cathode 9 of V. The contact points of relay RI designated as l3 and I4 are normally open; when closed, they complete the circuit through the battery B to the primary of the transformer P and interrupter I, thus producing a series of shock-impulses across the secondary S of the transformer, or between Fl and ground as interrupter I functions. Operation of the device is as follows: An animal crowds against the fence, and thus makes contact either between F2 and ground through body resistance, or between Fl and F2 and ground; however, a contact with Fl is also a contact with ground through the secondary of the transformer S which has sufliciently low resistance to pass enough current from the battery B to actuate the tube V. Current passes from battery B to ground through the transformer secondary S and back through the animal to F2 or directly to F2 from Fl in case the animal forces the wires to contact. Current then passes through potentiometer It to tube cathode 9 and back to battery B through the normally closed contacts of interrupter I. A portion of this current is supplied to grid ll] of tube V causing the tube to become conductive and to allow a current to flow from cathode 9 to plate In through coil l5 of relay Rl to battery B. Relay contacts l3 and I4 are caused to close and this action completes the circuit to the primary P of the transformer through interrupter I, however, as soon as the interrupter I points open, the circuit to the control tube cathode is broken, the tube is extinguished, the armature of relay RI opens, and a shock impulse is transferred to the fence. Note that condensers C2 and C3 may be omitted without seriously affecting the operation of the device when used as shown in Fig. 2. However, these condensers will be needed to bypass shock-impulses when the device is used with one wire as shown in Fig. 3. Fig. 3 shows the same mechanism of Fig. 2, connected to function with a single wire and ground return. When used in this way, it is desirable to add a choke coil Ch in'series with the grid l8 and potentiometer IE to keep shock-impulses from backfiring through tube V. Fig. 3 also shows the use of expansion and contraction of hygroscopic material I!) to actuate the arm of potentiometer l6 and afford automatic control of input sensitivity. Hygroscopic material l9 is fastened at one end to support I! and to the other end to the arm of potentiometer l6, while spring l8 attached to support ll serves to maintain tension on the potentiometer arm to enable its control by l9, and this control is preferably effected by means of a system of gears and/or levers used to multiply the very minute motion of l9. I have omitted mechanical details of such a system of gears or levers because the construction of such devices is not beyond average mechanical skill. Operation of Fig. 3 is as follows: An animal touching fence wire F2 completes the circuit from the battery B through the secondary of the transformer S to ground, and through the animal from ground to F2, and through F2 to potentiometer It, to cathode 9 of tube V and back to battery 13 through the normally closed points of interrupter I. A portion of the voltage across potentiometer H5 is transferred through the choke coil Ch, which has a low D. C. resistance, to the grid ll) and this voltage renders the tube V conductive and allows a current to flow from cathode 9 to plate ll through coil l5 of relay Rl to battery B. Relay contacts l3 and I4 are closed by magnetic attraction and condenser C2 is charged. Condenser C2 has sufiicient capacity to store up enough current to hold the relay points closed until the interrupter I has had an opportunity to open and close several times and send several shock impulses back through the fence. Since Fl has been disconnected temporarily as shown in Fig. 7, the shock impulse must pass from the secondary of the transformer S back through relay contacts l3 and I4, through the primary P to the cathode of tube V and through C3 to wire F2, and from F2 through the animal to ground. If wire Fl is used (as shown in Fig. 2) the shock impulses pass directly from Fl through the animal to ground, and C3 is not needed. Otherwise, the omission of C3 would result in a weak shock output, owing to the resistance of potentiometer [6 which must be rather high to secure adequate sensitivity. In Figs. 2 and 3 I have shown a mechanism that may be used in three different ways: (a) As a simple impulse generator with the fence connected to Fl and switch 2!! closed. (b) With transposed fence wires as shown in Fig. 2. (0)

With a single fence wire F2 and ground return to provide electronic impulse control as shown in Fig. 3. A wide variation of battery voltage is permissible with proper design of component parts. It is assumed that a battery with 2. voltage of from 6 to will ordinarily be used, and it is believed that most satisfactory operation will be secured if an ordinary 45-volt radio 3" battery is used as the source of current.

(A battery is shown as the source of current in Figures 1 to 3, inclusive, but any other source of electric energy could be used by employing suitable transformers and rectifiers to provide an output equivalent to that of the battery.)

In making an analysis of Figures 1, 2 and 3, it is desirable to point out that (as shown in Figure 2) bypass condensers C2 and C3 may be omitted without rendering the device inoperative. These condensers would normally be included to secure greater and more uniform shock output, but their removal does not prevent the instrument from working. The choke coil Ch shown in Figure 3 may likewise be omitted since its primary function i to protect tube V from surge voltage discharges. In Figure 3 it is obvious that the potentiometer l6 may be manually adjusted as shown in Figures 1 and 2 rather than through the expansion of some material which is actuated by moisture in the air. While the above mentioned parts are very desirable to make a smooth working instrument, they are not to be regarded as essential.

I have shown the evolution of an improved method whereby a fence controller can be made to operate only when an animal touches the fence enclosure, and this constitutes the basis of my invention. I believe my method of accomplishing this to be new, and that I am the original inventor of this new system of electric fenc- I have avoided showing any particular details of mechanical construction of controller mechanisms as it is obvious that an infinite number of mechanical variations is possible without alteration of the fundamental principles of operation as outlined above in my patent application.

Having thus described my invention, what I claim as new is:

1. In combination with a fence structure insulated from the ground, a fence transformer with a primary winding in series with a battery and the normally closed contact points of an interrupter, an electromagnetic relay with normally open contacts in series with the plate of a threeelement cold-cathode electron control tube connected to cause the operation of the said electromagnetic relay whenever there is a drop in the resistance between the grid and cathode of the said control tube, a condenser in parallel with the interrupter points, a condenser in parallel with the relay coil, a potentiometer connected between the grid and cathode of the said control tube and the fence circuit, a condenser in parallel with the said potentiometer, an iron core choke coil in eries with the said potentiometer contact arm and the grid of the said control tube, and hygroscopic material attached to move the contact arm of the said potentiometer with changes in relative atmospheric humidity.

2. In combination with a fence structure consisting of fence wires insulated from the ground, a fence transformer with a primary coil in series with a battery, the normally closed contacts of an interrupter, and the normally open contacts of an electromagnetic relay; a three-element electron control tube connected to cause the operation of the electromagnetic relay with a drop in resistance between the grid and cathode of the said tube, a condenser in parallel with the interrupter contact points, a potentiometer connected between the grid and cathode of the said tube and the fence circuit, a condenser in parallel with the said potentiometer, an iron core choke coil in series with the said potentiometer contact arm and the grid of the said control tube, a condenser in parallel with the coil of the said electromagnetic relay, and hygroscopic material attached to move contact arm of said potentiometer with changes in relative atmospheric humidity.

3. In combination with a fence structure consisting of fence wires insulated from the ground, a fence transformer with a primary winding in series with the normally closed contact points of an interrupter, a battery, and the normally open contacts of an electromagnetic relay, and with the secondary of the said fence transformer connected to the battery and between a fence wire and ground; a three-element cold cathode electron control tube connected to the fence to actuate the said electromagnetic relay with a drop in resistance between the said fence and ground; a condenser in parallel with the interrupter contact points, a potentiometer connected between the grid and cathode of the said control tube and the fence circuit, a condenser in parallel with the resistance winding of said potentiometer, an iron core choke coil in series with the said potentiometer arm and the grid of the said control tube, a condenser in parallel with the coil of the said electromagnetic relay, and hygroscopic material attached to move the contact arm of the said potentiometer with changes in the length of the said hygroscopic material due to the expansion and contraction with changes'in relative atmos pheric humidity.

4. In combination with a fence insulated from the ground, a battery in series with the primary of a transformer, an interrupter, and the normally open contacts of a separate relay; with the said relay coil connected in series with the plate circuit of a three element cold-cathode control tube; and with the grid of said tube connected through a variable potentiometer to the fence, and the cathode connected to the battery through the interrupter.

5. In combination with an insulated fence structure, a battery in series with the primary and secondary of a transformer, an interrupter having a condenser in parallel with its normally closed contact points, and the open contacts of a relay switch; with the coil of the said relay switch connected in series with the plate circuit of a three element cold-cathode control tube; with the grid of the said tube connected through a variable potentiometer to the insulated fence structure, and the cathode connected to the battery through the interrupter contact points.

6. An electrical circuit consisting of an insulated barrier, a source of direct current insulated from the ground and connected to the said barrier; a transformer, a normally closed interrupter, and normally open relay contact points connected in series and to the current source; and with the coil of the said relay in series with the plate circuit of a three element cold-cathode control tube, with the cathode of the said tube connected to the primary circuit of the fence transformer, and the grid connected to the barrier through a variable potentiometer.

7. In combination with separate fence structures insulated from the ground and from each other, a battery in series with the primary of a transformer, a normally closed interrupter, and the normally open contacts of a single pole double throw relay switch mechanism having its normally closed contact connected to the cathode of a three element vacuum tube, with the coil of the said relay in series with the plate circuit of the said tube, and with the grid of the said tube connected through a potentiometer between the cathode and one of the insulated fence structures; with the other insulated fence structure connected to the battery.

8. In combination with separately insulated and ungrounded fence structures, a source of current insulated from the ground and in series with the primary of a transformer having an attached interrupter by-passed by a condenser, and also in series with the two normally open contacts of a relay switch; with the coil of the said relay switch in series with the plate circuit of a three element cold-cathode vacuum tube; with the cathode of the said tube connected to the transformer primary; the grid of the said tube connected to a fence structure through a potentiometer between one fence structure and tube cathode; and with the other fence structure Number connected to the secondary of the transformer 2,172,050 and to the source of current. 2,090,199 2,210,211 LYMAN E. GREENLEE. 5 1,483,005 2,350,290 REFERENCES CITED 2,023,335 The iollowing references are of record in the 2,229,856 file of this patent: 10 2,198,715

UNITED STATES PATENTS Number Name Date Number 1,738,299 Kille Dec. 3, 1929 109,051

Name Date Mayberry Sept. 5, 1939 Heidger Aug. 17, 1937 Levenberg Aug. 6, 1940 McNair Feb. 5, 1924 Moore May 30, 1944 Heiken Dec. 10, 1935 Lorenz Jan. 28, 1941 Willis Apr. 30, 1940 FOREIGN PATENTS Country Date Australia Nov. 8, 1939 

